The renowned architect who designed Brooklyn’s embattled Atlantic Yards project says he now believes it will never be built because of the economic downturn.

In an interview with The Architect’s Newspaper, Frank Gehry yesterday referred to Bruce Ratner’s $4 billion plan to bring an NBA arena and 16 residential-office towers to Prospect Heights as one of several “unrealized commissions” he most wishes had been built.

“I don’t think it’s going to happen . . . That would be devastating to me,” he said.

Ratner said in a statement last night that it is “understandable” that Gehry and “others have concerns about this project happening in the worst economic environment since the Great Depression,” but the developer promised “Atlantic Yards will get built.”

Gehry later backtracked through a publicist, saying his comments to the trade publication were “misconstrued as a prediction” about the project and that he remains “hopeful it will come to fruition.”

Earlier this year, Ratner confirmed he’s trying to scale back costs on the glass-and steel arena Gehry designed for the NBA’s Nets to shave hundreds of millions of dollars off the estimated $950 million price.

He also shot down rumors in January that Gehry was canned from the project, but admitted bringing in engineers and other architects to seek cheaper ways to build.

In November, Gehry laid off about two dozen of his employees assigned to the project, sources said.

A Ratner spokesman yesterday said Gehry was still the project’s “lead architect,” but opponents of the controversial development said they doubt the architect is still involved because of his remarks about the project.

“If they’re saying he is the lead architect, he seems to be leading them nowhere,” said Daniel Goldstein, a spokesman for the group Develop Don’t Destroy Brooklyn.

Besides the economy, mounting litigation is holding up the project.

Late last year, the developer stopped all work until a lawsuit seeking to block Atlantic Yards is decided in the coming months.

More than two years after officials approved the project in December 2006, little work has been done, private land remains to be acquired, and Ratner is scrambling to keep the project afloat.

There is no timeline to compete the plan anymore. At best, construction on the arena and, perhaps, one of the skyscrapers could begin this year and possibly be completed by late 2011.